Showing papers in "Pain in 1976"
TL;DR: Most patients could readily use visual analogue and graphic rating scales despite having no previous experience and use of these scales is the best available method for measuring pain or pain relief.
Abstract: Of the different types of visual analogue and graphic rating scales tested in a series of experiments, only two were satisfactory: these were the visual analogue scale and the graphic rating scales used horizontally with the words spread out along the whole length of the line. Other types of scale used gave distributions of results which were not uniform. Unusual distribution of results occurred when patients selected a position adjacent either to descriptive terms or preferred numbers. In some experiments, the distribution of results was determined by the nature of the experiment. Alternation of the ends of a scale did not affect the results. The behaviour of the graphic rating scale was different in patients accustomed to completing it and in those not so accustomed. The results of pain severity measured by these methods showed a very good correlation with pain severity measured by the simple descriptive pain scale. Changes in visual analogue scores also correlated well with changes in simple descriptive pain scores. The visual analogue and graphic rating scales were more sensitive than the traditional simple descriptive pain scale. Most patients could readily use visual analogue and graphic rating scales despite having no previous experience. The failure rate was slightly lower with the graphic rating method. Use of these scales is the best available method for measuring pain or pain relief.
2,510 citations
TL;DR: The intent of this review is to examine and synthesize the extensive progress that has been made in the last few years describing the anatomical, physiological and neurohumoral substrates of neural systems which modulate pain perception.
Abstract: It has long been recognized that there are central nervous system mechanisms that can strikingly alter the perception of noxious stimuli. Indeed, recent theoretical treatments of pain have often given explicit recognition to this notion although little physiological detail has been available to support it [76,78,83]. The intent of this review is to examine and synthesize the extensive progress that has been made in the last few years describing the anatomical, physiological and neurohumoral substrates of neural systems which modulate pain perception. Particular progress has been made in elucidating a neural system which can be activated by electrical stimulation of certain brain stem structures as well as by the narcotic analgesic drugs. For this reason, considerable emphasis will be placed on explaining its mechanisms. However, we will also review some recent evidence showing that other neural systems as well participate importantly in the modulation of pain.
698 citations
251 citations
TL;DR: The analgesia resulting from electrical stimulation in the periventricular grey matter at the level of the posterior commissure in the human patient has been reversed by naloxone, raising the possibility that such stimulation is effective because morphine receptor cells may be activated.
Abstract: The analgesia resulting from electrical stimulation in the periventricular grey matter at the level of the posterior commissure in the human patient has been reversed by naxolone. This finding raises the possibility that such stimulation is effective because morphine receptor cells may be activated.
251 citations
TL;DR: The excitability of the class 3 cells was greater in spinal preparations but the tonic descending inhibition was weaker than the apparently similar descending tonic inhibition of class 2 cells.
Abstract: Single dorsal horn neurones have been recorded extracellularly in the lumbar spinal cord of cats anaesthetized with chloralose. Cold block at L 1 was used to provide reversible spinalization. The location of the units in the dorsal horn was marked by the electrophoretic deposition of pontamine sky blue from the recording microelectrode. There was a clear somatotopic representation of the ventrolateral surface of the foot in the L 6 segment. Thirty-five of the 46 units recorded in the marginal zone of the L 6 dorsal horn (lamina I) could only be excited by volleys in small afferent fibres and by noxious stimulation of the skin in the foot regions and were termed class 3 cells. The remaining 11 units could, in addition, be excited by sensitive cutaneous mechanosensitive afferent units — they were class 2 units. The ‘specific’ nociceptor-driven neurones could be divided into 2 subclasses on the basis of their excitability by afferent fibres. Class 3 (a) were excited only by Aδ cutaneous afferents and class 3 (b) by both Aδ and C cutaneous afferents. Some of the latter were also excited by Aδ and C afferent fibres in the lateral gastrocnemius nerve. When tested by natural stimulation all class 3 cells were excited by noxious mechanical stimuli, but only the 3 (b) units were effectively excited by heating the skin. This discharge in 3 (b) units could be suppressed by electrical stimulation of large (group II) cutaneous myelinated afferent fibres and a similar effect could be produced in responses evoked by Aδ and C afferent volleys. Additional inhibition was accomplished by electrical stimulation of the slower myelinated cutaneous (Aδ or group III) afferent fibres. The excitability of the class 3 cells was greater in spinal preparations but the tonic descending inhibition was weaker than the apparently similar descending tonic inhibition of class 2 cells. The results are discussed with reference to pain mechanisms.
237 citations
TL;DR: Against classical expectations were the following findings: localisation of touch and pressure stimuli was reasonably accurate on both sides, and repeated sub threshold stimulation markedly lowered the threshold for detecting von Frey hairs.
Abstract: The spinal cord of a patient had been completely and cleanly cut across at the Th3 segment except for part of one anterolateral quadrant. The extent of the lesion was clearly verified at an open surgical inspection. There was complete paralysis below the level of the lesion. The classical expectations of her sensory status were confirmed in only 2 ways: (1) Temperature could be identified only on the side opposite the intact quadrant. (2) Pin prick could be only identified on this contralateral side. Against classical expectations were the following findings: (1) Localisation of touch and pressure stimuli was reasonably accurate on both sides. (2) Passive movement could be detected on the homolateral side. (3) Pain could be evoked by stimulation of both sides. (4) Von Frey hair stimuli could be identified on both sides. (5) Repeated sub threshold stimulation markedly lowered the threshold for detecting von Frey hairs. This case implies that there must be a revision of the traditional labelling of the function of the spinal cord afferent systems.
232 citations
TL;DR: Although the mean scores are larger for acupuncture than for transcutaneous stimulation, statistical analyses of the data failed to reveal significant differences between the two treatments on any of the measures, and both methods appear to be equally effective.
Abstract: Twelve patients suffering chronic low-back pain were treated with both acupuncture and transcutaneous electrical stimulation. The order of treatments was balanced, and changes in the intensity and quality of pain were measured with the McGill Pain Questionnaire. The results, based on a measure of overall pain intensity, show that pain relief greater than 33% was produced in 75% of the patients by acupuncture and in 66% by electrical stimulation. The mean duration of pain relief was 40 h after acupuncture and 23 h after electrical stimulation. Although the mean scores are larger for acupuncture than for transcutaneous stimulation, statistical analyses of the data failed to reveal significant differences between the two treatments on any of the measures. Both methods, therefore, appear to be equally effective, and probably have the same underlying mechanism of action. Consideration of the advantages and disadvantages of the two methods suggests that transcutaneous electrical stimulation is potentially the more practical, since it can be administered under supervision by paramedical personnel.
204 citations
TL;DR: Positive results obtained support the theory according to which pain is caused by lack of proprioceptive stimuli reaching the thalamus, and improvements of electrodes and of the device are proposed.
Abstract: A number of patients with intractable pain were subjected to electrical stimulation of the nucleus ventralis posterolateralis. Positive results obtained support the theory according to which pain is caused by lack of proprioceptive stimuli reaching the thalamus. The implantation technique is discussed and improvements of electrodes and of the device are proposed. Optimal stimulation parameters are defined.
142 citations
137 citations
TL;DR: The results indicate that changes with age in pain perception are complex, involving not only possible discrimination deficits but also changes in bias for and against labeling noxious events as painful.
Abstract: The effect of age on ability to discriminate between levels of electrical stimulation of tooth pulp and willingness to report shocks as painful was evaluated using the Sensory Decision Theory. While threshold did not increase with age for tooth pulp stimulation as is often observed for thermal pain thresholds, a significant age deficit in ability to discriminate between suprathreshold shocks was observed. Significant changes with age in willingness to report the electrical shocks as painful were also observed. These results indicate that changes with age in pain perception are complex, involving not only possible discrimination deficits but also changes in bias for and against labeling noxious events as painful. These findings stress the need for within individual comparisons of laboratory techniques for evoking acute pain experiences where variables such as age are under consideration.
113 citations
TL;DR: “When all that is speculative and abstract is removed from Head’s contribution to this subject, there remains a most impressive body of observations that must have a permanent value and will serve as the material for a more realist interpretation.
Abstract: “When all that is speculative and abstract is removed from Head’s contribution to this subject, there remains a most impressive body of observations that must have a permanent value and will serve as the material for a more realist interpretation.” So wrote Walshe [loll at the end of his famous review on cutaneous sensation, in which by an intellectu~ tour de force as impressive as that of Head himself, he had succeeded in reducing the notions of ‘protopathic” and ‘epicritic’ to a laughing stock, Despite Walshe’s anathema, the terms ~p~ti~ul~ly protopathic) have been creeping back into the literature, and the time seems ripe for another review in the light of more recent clinical and physiological findings. The writers
TL;DR: A visceral pain test employing intraperitoneal injection of hypertonic saline which yields a writhing response in the adult rat more reliably than other painproducing substances.
Abstract: Numerous recent studies have demonstrated that electrical stimulation of the periaqueductal gray matter (PGM) can result in powerful analgesia to pain of somatic origin. In the present study, we have developed a visceral pain test employing intraperitoneal injection of hypertonic saline which yields a writhing response in the adult rat more reliably than other painproducing substances. With this test we show that writhing as well as the response to radiant heat (tail flick test) are completely inhibited in all animals with PGM electrode placements.
TL;DR: The effects of acupuncture were most pronounced at the lowest level of stimulation, while TES affected the perception of all levels of dental stimuli.
Abstract: The effects of acupunctural stimulation on the perception of induced dental pain were compared with those of placebo acupuncture and transcutaneous electrical stimulation (TES) at an acupuncture site. Each of 4 groups of 15 subjects received one of the following treatments: acupuncture, placebo acupuncture, TES, or control conditions. Every subject was tested twice, once in a baseline session and on another day in a test session. Four levels of painful dental stimuli were delivered repeatedly and in random order to each subject in each session, who rated the perceived intensity of each stimulus on a pain category scale. All three treatment groups showed a significant reduction in magnitude of stimulus ratings after treatment. A Sensory Decision Theory analysis of the data was employed to assess the sensory sensitivity of each subject to each of 4 levels of dental stimulation and the willingness of the subject to label the strongest stimulus as painful. Acupuncture and TES groups showed a small but significant sensory analgesic response to treatment and a significant reduction in willingness to identify the strongest stimulus as painful when contrasted to controls, but placebo acupuncture subjects failed to show significant change on either of the response measures. The effects of acupuncture were most pronounced at the lowest level of stimulation, while TES affected the perception of all levels of dental stimuli. The observed effects appeared to be small, reliable, and dependent on the stimulation of a particular anatomical locus.
TL;DR: By use of an organized team approach, a significant number of patients can be processed; and an overall reduction in use of alternative medical resources has occurred.
Abstract: A comprehensive treatment program for chronic disability related to back disease has been presented. This program has used not only more traditional methods of medical care for the structural disabilities of chronic mechanical back disorders, but has used principles of active patient participation in the improvement process. The patients are educated in the manifestations of pain behavior and in the phase II treatment program emphasis on pain sources is downgraded to allow positive reinforcement for healthy behavior to develop. By use of an organized team approach, a significant number of patients can be processed; and an overall reduction in use of alternative medical resources has occurred.
TL;DR: DSB was found to be complimentary to acupuncture therapy in that it facilitated patient selection for the therapy and resulted in maximum subjective improvement following acupuncture therapy performed at a later time.
Abstract: Forty patients with chronic pain below the waist level not amenable to conventional medical and/or surgical treatment were randomly assigned to one of two different methods of acupuncture, after studying the underlying pain mechanisms using a Multidisciplinary Pain Clinic approach and the differential spinal block (DSB). One group received acupuncture needling in the classical acupuncture points referred to as meridian loci needling (MLN) and the other group received tender area needling (TAN) with needles inserted in the dermatomal distribution of the painful areas. The responses between the two groups showed no significant difference. Results were then related to the predetermined somatopsychological basis of the individual's pain problems as classified by the DSB. A group of patients in whom pain relief occurred upon subarachnoid injection of 0.25% procaine followed by sympathetic blockade or 0.5% procaine injection followed by hypalgesia without motor loss, also reported maximum subjective improvement in their pain level following acupuncture therapy performed at a later time. The other group of patients in whom pain persisted despite sensory and motor blockade (1% procaine) responded very poorly to acupuncture therapy. DSB was found to be complimentary to acupuncture therapy in that it facilitated patient selection for the therapy.
TL;DR: It is found that in chronic painful conditions, needle puncture may be very effective in producing at least transient analgesia, and it also can produce permanent relief of acute (self‐limited) pains.
Abstract: The present study was undertaken in order to investigate the analgesic effect of needle puncture in a small self-selected group of patients with chronic or acute pain, and to examine the factors which determine success or failure of this treatment modality. We have found that in chronic painful conditions, needle puncture may be very effective in producing at least transient analgesia. It also can produce permanent relief of acute (self-limited) pains. Needle puncture was not helpful in the management of pain resulting from nerve damage. High score on psychometric indicators of anxiety and depression is a significant predictor of successful needle puncture analgesia in patients with chronic pain. Comparison of our results to studies of counterirritation indicate that the analgesia produced by needle puncture involves a mechanism similar to that of counterirritation-induced analgesia.
TL;DR: It is suggested that several substances might be released on antidromic stimulation of C fibres and that the resulting general excitation of sensory nerve terminals might play a role in modifying the central nervous system response to nociceptive information.
Abstract: Recordings were made from multifibre strands of the saphenous nerve of rats anaesthetized with urethane and given Evan's blue intravenously. Stimulation of A plus C fibres of the saphenous nerve, but not A fibres alone, at 10 Hz for 5 min produced dye leakage in the skin of the hind limb. Stimulation of the nerve at A plus C fibre voltages with the stimulating electrodes placed distal to the recording electrodes produced reversible block of nerve impulses at the stimulating electrodes. However, when the stimulating electrodes were placed proximal to the recording electrodes, stimulation of the nerve at A plus C fibre voltages, but not at A fibre voltages, produced an increase in activity in nerve strands. An increase in activity was also observed in experiments where the contralateral saphenous nerve was stimulated. These effects were not abolished by pretreatment of rats with reserpine. The early phase of the local oedema response appeared to be reduced by local pretreatment with compound 48 80 but the excitatory action on nerve terminals was not. The effects of nerve stimulation were not mimicked by intravenous injection of 5HT, ATP or adenosine into the contralateral saphenous vein. It is suggested that several substances might be released on antidromic stimulation of C fibres and that the resulting general excitation of sensory nerve terminals might play a role in modifying the central nervous system response to nociceptive information.
TL;DR: An analysis of the language of pain complaints, employing categories of descriptors, was used to determine if chronic pain of either psychiatric or organic origin might be depicted in terms specific for the disease.
Abstract: An analysis of the language of pain complaints, employing categories of descriptors, was used to determine if chronic pain of either psychiatric of organic origin might be depicted in terms specific for the disease. The complaints of 128 patients with chronic pain were studied for characteristic patterns. Patients with pain of organic etiology used sensory-thermal (e.g., hot, burning) words more frequently than those with pain of psychiatric origin. Female patients with pain attributed to anxiety used sensor-temporal words (e.g., throbbing) more frequently than those with other psychiatric diagnoses. There was also a statistically significant preponderance of pain on the left when the groups of patients with physical and psychological illness were combined.
TL;DR: Patients referred for the management of intractable pain, completed a 52‐item Illness Behaviour Questionnaire (IBQ), and syndromes resembling ‘hysteria, ‘conversion reaction’, and ‘hypochondriasis’ respectively were presented.
Abstract: One hundred patients, referred for the management of intractable pain, completed a 52-item Illness Behaviour Questionnaire (IBQ). Responses were scored on 7 scales: general hypochondriasis, disease conviction, psychological versus somatic perception of illness, affective inhibition, affective disturbance, denial, and irritability. IBQ scale profiles were subjected to numerical analysis and 6 taxonomic clusters were identified. Patients in groups 1-3 were characterized by a relatively non-neurotic, reality-oriented attitude to illness, as indicated by low scores on the first three scales. Patients in groups 4-6 manifested greater evidence of 'abnormal illness behaviour', and presented syndromes resembling 'hysteria', 'conversion reaction', and 'hypothchondriasis' respectively.
TL;DR: The course and termination of ascending degenerating fibers were studied and it was concluded that the terminations of the ventral and lateral spinothalamic fibers were largely similar.
Abstract: Four anterior cordotomies were performed in the cervical cord of macaques. “No detectable neurological deficit resulted” from this operation. The course and termination of ascending degenerating fibers were studied. The total conclusion was that the terminations of the ventral and lateral spinothalamic fibers were largely similar, the ventral tract making some connections that the lateral tract does not. Only the lateral tract sends fibers to the nucleus centralis lateralis, centrum medianum and the parafascicular complex of the medial thalamus.
TL;DR: The results of this study have established a phenomenon of acetylcholine-induced antinociception and identified the central, muscarinic nature of this response and implicate the possible involvement of central cholinergic mechanisms in the ant inociceptive action of morphine.
Abstract: Antinociceptive activity of intraventricularly administered acetylcholine was quantitated in mice by the tail-flick and phenylquinone tests. Acetylcholine was administered intraventricularly under light ether anesthesia in a 5 mul volume of sterile saline and mice were retested 10 minutes after the operation. A dose-response curve was established for acetylcholine (ED50 equals 7.3 mug) which was potentiated by intraventricular neostigimine and blocked by intraperitoneal atropine, but not by atropine methyl nitrate or mecamylamine. The antinociceptive effect of morphine was potentiated by intraventricularly administered acetylcholine. The acetylcholine-induced antinocieption was blocked by five narcotic antagonists in the same rank order of potency in which they antagonized the effects of morphine. However, the stereo-specificity of two narcotic antagonists, pentazocine and cylcazocine, was reversed in blocking acetylcholine and morphine-induced antinociception. The results of this study have established a phenomenon of acetylcholine-induced antinociception and identified the central, muscarinic nature of this response. In addition, several experiments have demonstrated similarities between this phenomenon and morphine-induced antinociception. These data implicate the possible involvement of central cholinergic mechanisms in the antinociceptive action of morphine.
TL;DR: The technical problems of stimulating intact teeth in clinical diagnosis and in pain research are discussed and circuits are given for isolated 100 V and 1kV constant current stimulators.
Abstract: The technical problems of stimulating intact teeth in clinical diagnosis and in pain research are discussed. Bipolar stimulation has no advantage over monopolar stimulation for most applications. A 100 V constant current stimulator is suitable for monopolar stimulation of healthy teeth with a large electrode at about threshold intensity, but, for monopolar stimulation up to 150 micronA and for bipolar stimulation, very much higher voltages are required and no suitable instrument is available. Circuits are given for isolated 100 V and 1kV constant current stimulators.
TL;DR: It is concluded that factor (s) exist in the serum during migraine attacks, which can cause 5‐HT release from normal platelets, and the identification of this factor may be important.
Abstract: Experiments were carried out in order to further delineate the pathophysiology of the fall of plasma 5-hydroxytryptamine (5-HT) during a migraine attack. Platelets from normal subjects were incubated with 14C-labelled 5-HT, and the release of 5-HT was measured following exposure of these platelets to plasma taken from migraine patients during an attack or at headache-free intervals. Plasma taken during attacks released significantly more 5-HT. It is concluded that factor(s) exist in the serum during migraine attacks, which can cause 5-HT release from normal platelets. The identification of this factor may be important.
TL;DR: Examination of the adjectives indicated that intensity relates to ‘affective‐evaluative’ adjectives rather than ‘sensory’ ones, which could have implications for the language a patient may use to communicate the intensity of a pain.
Abstract: Thirty-nine adjectives which may be used to describe a pain experience were rated on an ‘intensity’ continuum by 93 subjects, and in a second study by an additional 90 subjects. In each study these ratings were intercorrelated and factor-analyzed. The first 6 factors extracted were rotated to a simple structure criterion. The first factor was identified as an ‘intensity’ factor. Examination of the adjectives indicated that intensity relates to ‘affective-evaluative’ adjectives rather than ‘sensory’ ones. The implications of these findings for the language a patient may use to communicate the intensity of a pain are discussed.
TL;DR: Overall lack of association between chronicity and illness behaviour remained even when the patient sample was restricted to those 20 patients having substantial organic pathology associated with their pain, suggesting that degree of chronicity is unlikely to play a major role in determining the illness behaviour manifested by patients with intractable pain.
Abstract: One hundred patients, referred for the management of intractable pain, completed a 52-item Illness Behaviour Questionnaire (IBQ). Responses were scored on 7 scales: General hypochondriasis, disease conviction, psychological versus somatic perception of illness, affective inhibition, affective disturbance, denial and irritability. IBQ scale profiles were used to study the relationship between chronicity of pain and pattern of illness behaviour reported. Except in the case of one scale, no significant correlation emerged. This overall lack of association between chronicity and illness behaviour remained even when the patient sample was restricted to those 20 patients having substantial organic pathology associated with their pain. These findings suggest that degree of chronicity is unlikely to play a major role in determining the illness behaviour manifested by patients with intractable pain.
TL;DR: Dopamine and serotonin appear to facilitate SPA, whereas noradrenaline appears to inhibit it, suggesting the existence of a common pain-inhibitory system in the brain activated by morphine and by focal electrical stimulation.
Abstract: The roles played by the cerebral mono~ines (dopamine, noradrenaline and serotonin) in stimulation-produced analgesia (SPA) have been investigated in the rat employing the tail flick test. SPA was elicited through bipolar electrodes chronically implanted in the mesencephalic periaqueductal gray matter. Four approaches were used to alter tr~smission in mono~ine pathways. (1) Depletion of monoamines by administration of tetrabenazine (TBZ), p-chlorophenylalanine (PCPA), alpha-methyl-para-tyrosine (AMPT) or disulfiram. (2) Replacement of depleted monoamine stores by appropriate precursors (5-HTP or L-DOPA), (3) Potentiation of monoamine systems by administration of precursors to previously untreated animals or by the administration of a dopamine receptor stimulator, apomorphine. (4) Blockade of catecholamine receptors by haloperidol or of dopamine receptors by pimozide. These 4 approaches yielded internally consistent results. Depletion of all 3 monoamines (TBZ) led to a powerful inhibition of SPA. Original levels of SPA were restored by injection of either 5-HTP or L-DOPA. Specific depletion of serotonin (PCPA) caused a reduction in SPA, whereas elevation of serotonin levels (5HTP) caused an increase in SPA. Dopamine receptor blockade decreased and apomorphine increased SPA. On the other hand, selective depletion of noradrenaline (disulfiram) caused an increase in SPA. Thus, dopamine and serotonin appear to facilitate SPA, whereas noradrenaline appears to inhibit it. Some striking parallels between SPA and morphine analgesia are noted. These suggest the existence of a common pain-inhibitory system in the brain activated by morphine and by focal electrical stimulation.
TL;DR: The neurostimulators lower the clinical pain level component of the tourniquet test score for non‐surgery patients to a degree comparable to that of patients with successful surgical outcomes, but maximum pain tolerance is not significantly altered, which supports the hypothesis that the analgesic effect is primarily a peripheral one.
Abstract: One year follow-up data are analyzed for the effects of using transcutaneous neurostimulators on patients with chronic benign pain. Those who have successful surgery for pain relief have lower pain and analgesic intake levels than those who supplement their surgery with neurostimulation. Those who do not receive surgery for pain but use neurostimulators have greatly increased activity levels than those who do not use these devices. The neurostimulators lower the clinical pain level component of the tourniquet test score for non-surgery patients to a degree comparable to that of patients with successful surgical outcomes, but maximum pain tolerance is not significantly altered. This supports the hypothesis that the analgesic effect is primarily a peripheral one.
TL;DR: Recordings of neural responses evoked by stimulation of dentine with solutions of NaCl, NH4Cl and dextrose suggest that the receptors were in the innermost dentine or the pulp and that they were excited by changes in extracellular fluid composition rather than by osmotic effects.
Abstract: Recordings have been made of the neural responses evoked by stimulation of dentine with solutions of NaCl, NH4Cl and dextrose Stimulation of the outer dentine produced no response From the inner dentine, a smaller number of impulses were recorded with solutions of NaCl than with corresponding concentrations of NH4Cl, but a much larger number than with solutions of dextrose The discharge evoked by a solution increased in mean frequency and decreased in latency as the thickness of dentine was reduced The responses suggest that the receptors were in the innermost dentine or the pulp and that they were excited by changes in extracellular fluid composition rather than by osmotic effects The properties of the receptors appear to be different from those involved in pain from dentine in man